Carbon-based nozzle thermochemical erosion characteristics in solid rocket motors

Based on the thermochemical erosion theory, a two-dimensional axisymmetric, coupled gas-solid-thermal numerical framework was established to predict the carbon-based nozzle erosion in solid rocket motors. Numerical simulations were carried out using the Wall Surface Reaction model of the commercial code FLUENT and the assumption whether the erosion process was chemical kinetics or diffusion controlled was not needed. The method was introduced to simulate the 70-lb BATES motor nozzle erosion and examine the effects of propellant composition, oxidizing species and chamber pressure. The calculated results agree well with experimental data. The erosion rate follows the trend exhibited by the heat flux distribution, and peaks slightly upstream of the throat. The erosion rate decreases with increasing aluminum content and increases almost linearly with chamber pressure. H ₂O is the dominant oxidizing species in dictating nozzle erosion.